This method may not bring the battery to full performance of the original condition but at my rate the battery will work for 50%~70% of it's initial value.
- 3cm syringe
- voltmeter or multimeter
- battery charger
- crocodile cords"
- Distilled water
use goggles and chemical gloves
don't touch the water that comes out of the battery it's acid
STEP 1: PREPARING THE BATTERY
in sealed battery we will find cover on the top of the battery
just remove it by little flat screw driver like photo
when finish we will find 3 or 6 holes covered by rubber caps
now we have to remove this caps too.
we will measure volts of this battery
on my battery it's 0.76 volts only. that's mean the battery is completely dry from inside
STEP 2: FILL THE WATER INSIDE THE BATTERY
we need in this step to fill the battery with Distilled water to activate the acid again
so refill it by syringe few time until the water come out from all holes and measure the voltage
u will find it increased by some Volts
if not don't worry
STEP 3: MIX D WATER WITH ACID WHILE CHARGING
after filling the battery with the water we need to make sure it's mixed with dried acid inside the battery to reactivate it again
so first we will charge it with 12 volts DC "i'm using normal 12v charger" output is 16Amps
u can use any charger 12V in maximum 9V in minimum
ok now wait 5min until u see bubbles come out from the holes.
if no bubbles come from any of 3 holes u have to reverse negative and positive and wait 1~3min At Maximum (it's Dangerous step don't leave the battery in this condition alone)
now u must see bubbles come out from holes too fast like boiling cut off the power immediately and reconnect negative and positive right again
now pull the wasted water from the top of 3 holes by the syringe and let the battery charging
Don't cover holes until it charge to 6.9V u should check it every 1 hour
then dry it out by tissue and cover every thing and continue charging properly.